Casting ( Screen mirroring) failure in OnePlus 3T

Why I am not able to cast ( screen mirroring) OnePlus 3T to Samsung smart TV . I heard many have same problem who purchased OnePlus 3T. Simply it mean there should be issue in software in original OnePlus 3T brand new hand set . Does it mean there is factory defect in many hand set.. I have already registered complaint with OnePlus support team for same issue.my complaint reference ( ID No)504981 but till date didn’t get any answer, response or any help. This handset OnePlus is available in India through Amazon since last just 2 weeks but unfortunately nobody from OnePlus 3T is giving any help with this issue. I tried everything as suggested Wipe cashes, Wipe data, factory reset for at least 4 to 5 times. What should I do now ? Should I send back it ? Tell me procedure how to sent it back and replace with brand new handset.. such type of experience is forcing me to never suggest OnePlus to any friends..
Expecting earliest favorable response..
Thanks